α-D-Glucosyl Transfer to Phenolic Compounds by Sucrose Phosphorylase from Leuconostoc mesenteroides and Production of α-Arbutin.

Transglycosylation from sucrose to phenolic and related compounds by sucrose phosphorylase (EC 2.4.1.7) from Leuconostoc mesenteroides was studied. The enzyme had a rather broad acceptor specificity and transferred glucosyl residue of sucrose to various acceptors such as hydroxybenzenes, hydroxybenzoic acids, benzyl alcohol, and hydroxybenzyl alcohols. The enzyme could transfer the glucosyl moiety of sucrose to phenolic OH groups and alcoholic (hydroxymethyl) OH groups, though not to carboxyl groups. The phenolic OH group was more effective than a hydroxymethyl group as the acceptor. Phenolic OH groups adjacent to hydroxyl, hydroxymethyl, or carboxyl groups had an increased effectiveness as acceptors. About 2.3 g of the purified transfer product was obtained from 2.0 g of hydroquinone. Its structure was identified as hydroquinone-O-α-d-glucopyranoside (α-arbutin) on the bases of the secondary ion mass spectrometry analysis, the component analysis of its enzymatic hydrolysates, and the carbon-13 nuclear magnetic resonance analysis. The browning resistance of α-arbutin to light irradiation was extremely increased compared to that of hydroquinone. The inhibitory activity on tyrosinase of α-arbutin was almost equal to that of arbutin.